Apparatus, system and method for power saving between a scheduling request and grant using self-learning

Abstract

A device and method for power saving between a scheduling request and a grant. A user equipment (UE) establishes a connection to a network, the UE and the network may be configured with a Connected Discontinuous Reception (C-DRX) functionality, the C-DRX functionality including a cycle with at least one onDuration. The UE transmits, during a first subframe a scheduling request (SR) to the network, the SR corresponds to data that is to be transmitted by the UE. The UE determines a second subframe for the UE to enter an active mode of processing for a reception of a grant, the second subframe is subsequent to the first subframe and prior to a next onDuration. The UE initiates an active mode of processing for the reception of the grant during the second subframe.

What is claimed: 
     
       1. A method, comprising:
 at a user equipment (UE) associating with an evolved Node B (eNB) to establish connection to a Long Term Evolution (LTE) network, the UE and the LTE network configured with a Connected Discontinuous Reception (C-DRX) functionality, the C-DRX functionality including a cycle with at least one onDuration:
 transmitting, during a first subframe a scheduling request (SR) to the LTE network, wherein the SR corresponds to data that is to be transmitted by the UE; 
 determining a second subframe for the UE to enter an active mode of processing for a reception of a grant, wherein the second subframe is subsequent to the first subframe and prior to a next onDuration; and 
 initiating the active mode of processing for the reception of the grant during the second subframe. 
 
 
     
     
       2. The method of  claim 1 , wherein determining the second subframe is based on a number of subframes between a transmission of a previous SR to the LTE network and reception of a previous grant subsequent to the previous SR. 
     
     
       3. The method of  claim 1 , wherein determining the second subframe is based on whether the connection is a frequency division duplexing (FDD) connection or a time division duplexing (TDD) connection. 
     
     
       4. The method of  claim 1 , wherein the grant comprises an uplink grant in response to the SR or a downlink grant. 
     
     
       5. The method of  claim 1 , further comprising:
 (a) determining whether a downlink data retransmission has been received without receiving a corresponding downlink grant; 
 (b) determining whether an uplink grant corresponding to the SR has not been received within a predetermined number of subframes from the first subframe; and 
 (c) when (a) or (b) is determined to be true, for a subsequent SR, determining a further second subframe that is different from the second subframe. 
 
     
     
       6. The method of  claim 1 , further comprising:
 monitoring a parameter related to an uplink channel between the UE and the LTE network; 
 determining that the parameter related to the uplink channel satisfies a predetermined condition; and 
 when the predetermined condition is satisfied, for a subsequent SR, determining a further second subframe that is different from the second subframe. 
 
     
     
       7. The method of  claim 1 , wherein during subframes between the first subframe and the second subframe, the UE is one of in a sleep mode or in an active mode for a portion of each of the subframes between the first and second subframe, and in the sleep mode for a remaining portion of each of the subframes between the first and second subframes, wherein the sleep mode comprises the UE turning off a receiver of the UE. 
     
     
       8. The method of  claim 7 , wherein when the UE is in the active mode for the portion of each of the subframes, the method further comprises:
 determining whether the grant was received during the portion of one of the subframes; and 
 when the grant was received during the portion of one of the subframes, for a subsequent SR, detecting a further second subframe that corresponds to the one of the subframes. 
 
     
     
       9. The method of  claim 1 , further comprising:
 performing the transmitting, determining and initiating operations for a plurality of SRs; 
 determining whether the grant corresponding to each of the SRs is received after the second subframe for a predetermined number of consecutive SRs; and 
 when the grants are received for the predetermined number of consecutive SRS, for a subsequent SR, detecting a further second subframe based on the reception of the grants. 
 
     
     
       10. A user equipment (UE) comprising:
 a transceiver configured to establish connection with an evolved Node B (eNB) corresponding to a Long Term Evolution (LTE) network, the UE and the LTE network configured with a Connected Discontinuous Reception (C-DRX) functionality, the C-DRX functionality including a cycle with at least one onDuration; 
 a processor configured to instruct the transceiver to operate in a first mode wherein the transceiver is in an active mode for all the subframes between a first subframe when a scheduling request (SR) is transmitted by the transceiver and a second subframe corresponding to a start of the onDuration, 
 the processor further configured to instruct the transceiver to operate in a second mode when the transceiver is in a sleep mode for at least one subframe between the first subframe and the second subframe. 
 
     
     
       11. The UE of  claim 10 , wherein in the second mode, a number of subframes for which the transceiver is in sleep mode is based on a number of subframes between a transmission of a previous SR and reception of a grant subsequent to the previous SR when the transceiver is in the first mode. 
     
     
       12. The UE of  claim 10 , wherein in the second mode, the processor monitors one of an uplink channel or a downlink channel between the UE and the eNB for a predetermined condition and when the predetermined condition is detected, the processor instructs the transceiver to operate in the first mode. 
     
     
       13. The UE of  claim 11 , wherein the predetermined condition comprises one of an uplink block error rate (BLER) exceeding a predetermined condition threshold, a downlink retransmission being received without a corresponding downlink grant being received or an uplink grant corresponding to the SR not being received prior to a predetermine number of subframes after the first subframe. 
     
     
       14. The UE of  claim 10 , wherein the transceiver is in the sleep mode for only a portion of the at least one subframe. 
     
     
       15. An integrated circuit, comprising:
 circuitry configured to establish a connection to a Long Term Evolution (LTE) network, the first circuitry and the LTE network configured with a Connected Discontinuous Reception (C-DRX) functionality, the C-DRX functionality including a cycle with at least one onDuration; 
 circuitry configured to generate for transmission, during a first subframe, a scheduling request (SR) to the LTE network, wherein the SR corresponds to data that is to be transmitted to the LTE network; 
 circuitry configured to determine a second subframe, during which an active mode of processing for a reception of a grant is initiated, wherein the second subframe is subsequent to the first subframe and prior to a next onDuration; and 
 circuitry configured to initiate the active mode of processing for the reception of the grant during the second subframe. 
 
     
     
       16. The integrated circuit of  claim 15 , wherein determining the second subframe is based on the connection being a time division duplexing (TDD) connection. 
     
     
       17. The integrated circuit of  claim 15 , wherein determining the second subframe is based on the connection being a frequency division duplexing (FDD) connection. 
     
     
       18. The integrated circuit of  claim 15 , wherein the grant comprises an uplink grant in response to the SR or a downlink grant. 
     
     
       19. The integrated circuit of  claim 15 , wherein determining the second subframe is based on a number of subframes between a transmission of a previous SR to the LTE network and reception of a previous grant subsequent to the previous SR. 
     
     
       20. The integrated circuit of  claim 15 , wherein during subframes between the first subframe and the second subframe, the device is in an active mode for a portion of each of the subframes between the first and second subframe and in a sleep mode for a remaining portion of each of the subframes between the first and second subframes, wherein the sleep mode comprises the device turning off a receiver of the device.